Method of manufacture of a composite shared pole design for magnetoresistive merged heads and device manufactured thereby

ABSTRACT

A merged read/write magnetic recording head comprises a low magnetic moment first magnetic shield layer over a substrate. A read gap layer with a magnetoresistive head is formed over the first shield layer. A shared pole comprises a low magnetic moment second magnetic shield layer plated on a sputtered seed PLM layer over the read gap layer, a non-magnetic layer plated over the PLM layer and a HMM lower pole layer plated over the second magnetic shield layer. A write gap layer is formed over the first high magnetic moment pole layer of the shared pole. An upper pole comprises a high magnetic moment pole layer over the write gap layer.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to thin film magnetoresistive (MR) headsand more particularly to magnetoresistive (MR) head structures.

[0003] 2. Description of Related Art

[0004] U.S. Pat. No. 5,639,509 of Schemmel for “Process for Forming aFlux Enhanced Magnetic Data Transducer” shows a two layered polestructure with a magnetic High Moment Material (HMM) layer 48 formedover a magnetic Permalloy-Like Material (PLM) 42. A flux enhanced datatransducer and method for producing the same in conjunction with sharedshields on magnetoresistive (MR) read heads in which substantiallybetween 500 Å-2500 Å of a relatively higher magnetic moment material isadded to the upper surface of the shared shield, or bottom write headpole, prior to a magnetic flux containment ion milling operationutilizing the upper pole as a mask. The relatively higher magneticmoment flux enhancement layer may comprise CoNiFe, FeN or similarmaterial which is deposited prior to the formation of the dielectric gaplayer. The flux enhancement layer may then be selectively removedsubstantially surrounding the upper pole by means of a relatively briefion milling process in which only on the order of 1,000 Å of the layerneed be removed and during which only an insignificant amount of thematerial removed might be re-deposited on the sides of the upper pole.

[0005] U.S. Pat. No. 5,606,478 of Chen et al. for “Ni₄₅Fe₅₅ Metal-in-GapThin Film Magnetic Head” and U.S. Pat. No. 5,812,350 of Chen et al. for“Metal-in-Gap Thin Film Magnetic Head Employing Ni₄₅Fe₅₅” show a polepiece P1 composed of a combination of HMM and LMM materials.

[0006] U.S. Pat. No. 5,435,053 of Krounbi et al. for “Simplified Methodof Making Merged MR Head” shows a method for making a planarized mergedpole.

SUMMARY OF THE INVENTION

[0007] With the continuous trend in the magnetic recording industry ofincreasing of the track density of magnetic recording, the objective ofreduction of edge erasure from adjacent track writing becomesincreasingly important. Edge erasure, resulting from writing fringe, candecrease the written track width and reduce drive yield by degradingoff-track capacity and/or unwanted overwriting of adjacent tracks whenwriting. The writing fringe field often comes from a dimensionalinconsistency and a mismatch of materials near the area where the fluxis crowded, i.e. the gap area, of write heads. Recording onhigh-coercivity media especially requires the heads made of High MomentMaterial (HMM) for write poles and Permalloy-Like Material (PLM) formagnetoresistive (MR) shields.

[0008] Magnetic poles made of materials with a saturation magnetizationhigher than that of Permalloy are desirable for improving thewritability of magnetic recording heads.

[0009] We have found that there is a need for a merged magnetoresistive(MR) recording heads with both High saturation Moment Material (HMM) andPermalloy. The HMM material is suitable for recording on high-coercivitymedia. Permalloy or Permalloy-Like Material (PLM) can function as a goodsensor shield.

GLOSSARY

[0010] Edge erasure—Erasure by the write head that occurs outside of twoedges of the the write track.

[0011] Writing fringe—Unintended writing along two edges of the desiredwrite track.

[0012] Writing fringe-field—the magnetic field outside of the write gapcausing inadvertent writing along two edges of the desired write track.

[0013] Overwrite—The process of writing on a disk track to erasepreviously written information while simultaneously writing new data.

[0014] Side writing—Unintended writing on two sides of a track. It mayadversely affect data recorded on an adjacent track.

[0015] HMM—High Moment Material electroplated metals and alloys havinghigh saturation moments or saturation magnetization (4πM_(s))characteristics such as Ni₄₅Fe₅₅, Ni₄₅Fe₅₅Sn, CoNiFe, CoFeCu,Ni₄₅Fe₅₅Cr, and Ni₄₅Fe₅₅Mo.

[0016] Permalloy—A nickel rich alloy with iron, with a ratio just below5:1 Ni atoms to Fe atoms, Ni₇₉Fe₁₉.

[0017] Permalloy Like Material—PLM

[0018] PLM—Permalloy Like Material consists of all electroplated metalsand alloys having soft-magnetic properties such as Permalloy (Ni₇₉Fe₁₉),NiFeCr, NiFeMo, NiFeW, NiFePd, NiFeCu, NiFeCo in which the ratio ofnickel atoms to iron atoms is about 5:1 with fewer high magnetic momentiron atoms.

[0019] ABS—Air Bearing Surface—pole tips are separated by an air gap atan ABS.

[0020] IBE—Ion Beam Etching

[0021] A method of manufacturing a magnetic recording head includes thefollowing steps. Form a low magnetic moment first magnetic shield layerover a substrate.

[0022] Form a read gap layer with a magnetoresistive head over the firstshield layer.

[0023] Form a seed layer over the read gap layer.

[0024] Form a frame mask with width “W” over the seed layer.

[0025] Form a low magnetic moment second magnetic shield layer over theread gap layer over the seed layer.

[0026] Form a non-magnetic spacer layer over the second magnetic shieldlayer.

[0027] Form a first high magnetic moment pole layer over the secondmagnetic shield layer.

[0028] Form a write gap layer over the first high magnetic moment polelayer.

[0029] Form a second high magnetic moment pole layer over the write gaplayer.

[0030] Outside of the frame mask perform the step of removing theportions the second magnetic shield layer, the first high magneticmoment pole layer, the write gap layer, the second high magnetic momentpole, and the seed layer.

[0031] Preferably, employ ion beam etching to narrow the lower polelayer and the write gap layer to upper magnetic pole width “N” wherewidth “W” is substantially greater than width “N”, and employ ion beametching to pattern the first high magnetic moment pole layer to magneticpole width “N” in part and flaring the remainder of the first highmagnetic moment pole layer towards the width “W” of the second magneticshield layer. As a result, the upper high magnetic moment pole layer hasa narrow width “N”, the second magnetic shield layer has a width “W”over the second magnetic shield layer. Narrow the lower pole layer andthe write gap layer to upper magnetic pole width “N” where width “W” issubstantially greater than width “N”, and pattern the first highmagnetic moment pole layer to magnetic pole width “N” in part andflaring the remainder of the first high magnetic moment pole layertowards the width “W” of the second magnetic shield layer. Thisstructure is fashioned by using the upper pole as a mask to trim theupper high magnetic moment layer of the shared pole so that the highmagnetic moment layer has the same dimension “N” as the top pole and itsbottom part is wider with a width “W”.

[0032] Form a nonmagnetic spacer layer over the low magnetic moment,second magnetic shield layer, and below the lower pole layer.

[0033] The low magnetic moment second magnetic shield layer over theread gap layer is formed of a material selected from the groupconsisting of metals and alloys having soft-magnetic propertiesincluding Permalloy, NiFeCr, NiFeMo, NiFeW, NiFePd, NiFeCu, and NiFeCo,and the lower pole layer is formed of a material selected from the groupconsisting of Ni₄₅Fe₅₅, Ni₄₅Fe₅₅Sn, CoNiFe, CoFeCu, Ni₄₅Fe₅₅Cr, andNi₄₅Fe₅₅Mo.

[0034] Sputter a PLM nickel-iron seed layer over the read gap layerprior to plating the low magnetic moment second magnetic shield layer.

[0035] Another aspect of this invention is the merged magnetic readhead/write head structure produced by the above process.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The foregoing and other aspects and advantages of this inventionare explained and described below with reference to the accompanyingdrawings, in which:

[0037]FIG. 1 shows a first embodiment of this invention is providing amerged magnetoresistive (MR) head with a PLM shield layer laminated withan HMM lower pole layer.

[0038]FIG. 2 is a sectional view of a second embodiment of the device ofFIG. 1 and FIG. 2 is a section taken along taken along line 2-2 in FIG.6.

[0039]FIGS. 3A and 3B show the results of measurement of easy axis loopswhich indicate that a Structure B, shown in FIG. 3B has one compositecoercivity; whereas a Structure A, shown in FIG. 3A, possesses thecoercivities of both materials.

[0040]FIG. 4A-4I shows successive steps in a process of manufacturing adevice similar to the device of FIG. 2 in accordance with the method ofthis invention.

[0041]FIG. 5 is a sketch mapped of the stray fields frommagnetoresistive (MR) magnetic heads.

[0042]FIG. 6 shows a fragmentary sectional view of a device inaccordance with this invention showing the second embodiment of thisinvention shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0043] Tapping an MFM tip on an Air Bearing Surface (ABS) of energizedwrite heads was carried out to study the stray field of the tip. Thestray fields from heads were mapped and studied as indicated by thesketch in FIG. 5. In this study, we concluded that shared polerequirements are as follows:

[0044] 1. Shared poles require use of HMM materials near the write gapin order to reduce saturation and fringe fields, and

[0045] 2. Dimensional changes from the write gap to the shared poleshould neither be near to the read gap nor near to the write gap.

First Embodiment

[0046] The basic structure of a first embodiment of this invention isshown in FIG. 1 which provides a merged magnetoresistive (MR) head 10with a PLM shield layer laminated with an HMM lower pole layer formedabove a shield layer S1. Read gap layers RG composed of a non-magneticdielectric material are formed over the shield S1 with amagnetoresistive sensor stripe MRS sandwiched within the read gap layersRG, as will be well understood by those skilled in the art.

[0047] In accordance with this invention, as shown in FIG. 1 and FIG. 2,above read gap layer RG, a seed layer SL is formed on which a sharedlower pole LP is formed comprising a pair of laminated layers S2A/S2B.The shared lower pole LP combination is formed by a lower PLM layer S2Aplated on seed layer SL and an upper HMM layer S2B plated on the lowerlayer S2A. Thus, layer S2A of the lower pole LP is formed on the topsurface of seed layer SL which is formed on the top surface of the readgap layers RG. The upper HMM layer of Lower pole LP which comprises thefirst High Magnetic Moment (HMM) layer S2B is formed above layer S2A andit is one of a pair of HMM layers which comprise the material of thepoles adjacent to the write gap layer WG which is formed on the topsurface of HMM layer S2B.

[0048] The write gap layer WG is also composed of a non-magneticdielectric material, which is formed over the HMM layer S2B of the lowerpole LP.

[0049] The upper pole UP comprises a write head pole P composed of HMMmaterial formed on the surface of the write gap layer WG of the writehead. Thus the write gap layer WG is located between the first HMM layerS2B of the lower pole LP and the top, write head pole P.

[0050] The two HMM layers of poles LP and UP, including the first HMMlayer S2B and pole P, make it possible for the write head to record onhigh-coercivity magnetic recording media; while at the same time the PLMlayer S2A of the shared lower pole LP functions as a goodmagnetoresistive (MR) sensor shield for the magnetoresistive stripe MRS.

[0051] As stated above, the top, write head pole UP comprises an HMMlayer P with a narrow width “N”. The shared pole LP is made of astructure of HMM layer S2B sandwiched with a PLM layer S2A. The shaped,shared pole LP is patterned by a process of Ion Beam Etching (IBE) whichimproves the dimensional consistency between top pole UP and the sharedpole LP and the mismatch between the plated PLM layer and the two HMMlayers with a width “W” at the base of the lower HMM layer S2B.

[0052]FIG. 6 shows a fragmentary sectional view of a device 10′ showinga second embodiment of this invention. FIG. 2 is a sectional view of thedevice 10′ of FIG. 6 taken along line 2-2. FIG. 2 shows a modified head10′ based on the head 10 of FIG. 1 with the lower pole LP′ modified toform a layered structure in which the PLM layer 2A is separated from theHMM layer 2B by a non-magnetic, dielectric layer SP. The structure ofFIG. 6 shows the write coils WC in a dielectric layer D above the writegap layer WG and below the upper pole P. The remaining layers have beendescribed above in connection with the description of FIG. 1. In FIG. 6,the air bearing surface ABS is shown on the left end of the device 10′.The right end of device 10′ is broken away for convenience ofillustration.

[0053] In the case of the embodiment of FIG. 2, there is a keystructural modification comprising separation of HMM layer S2B from thefirst HMM layer 2B by a non-magnetic spacer layer SP. If a spacer layerSP is provided, as in FIG. 2, before plating HMM layer S2B, spacer layerSP is plated on top of a metal area on the surface of PLM metal layerS2A. The non-magnetic spacer layer SP allows the HMM/PLM layers toperform their individual functions freely with reduced magneticinteraction, while remaining in intimate physical proximity (on eithersurface of layer SP) separated by on the order of only about 75 Å-125 Åor preferably about 100 Å.

[0054] In both FIG. 1 and FIG. 2, the HMM layer S2B has verticalsidewalls SW extending from the top thereof to about half-way downtowards layer S2A. Then, referring to FIG. 1, the walls flair out from awidth “N” laterally forming tapered walls TW with a width “W” at thebase where walls TW reach the top surface of layer S2A or spacer layerSP. Walls TW are sloped at an acute angle of between about 10° and about35° so that first HMM layer S2B is of equal width to top HMM layer P atthe top thereof. Referring to FIG. 2, layer S2B has a full height FH,and layer S2B remains at a narrow width N for the height NH whichreaches about half way down height FH along the sidewalls SW. Then theHMM layer S2B flares out from width “N” to width “W” for the taperedheight TH. Thus layer S2B has a substantially width “W” at the bottom oftapered walls TW where it is proximate to contact with PLM layer S2Athan the narrow pole P with width “N”. The dimensions shown in FIGS. 1and 2 are substantially equal and the dimension markings are separatedfor clarity of illustration with FIG. 2 showing the heights of theportions of lower pole LP′.

[0055] The two examples of embodiments of this invention seen inFIGS. 1. and 2 are layered structures which have been investigated byapplicants and which are referred to hereinafter as structure A andstructure B. Structure A In structure A, the lower pole LP′ of FIG. 2includes the stacked layers as follows: PLM SP HMM 1 μm Ni₈₁Fe₁₉ / 100 ÅCu / 1 μm Ni₄₅Fe₅₅Sn_(0.3))

[0056] Structure A was made with a 100 Å thick copper (Cu) spacer layerSP between the PLM and HMM layers, as shown in FIG. 2. Structure B Instructure B, the lower pole LP′ of FIG. 1 includes the stacked layers asfollows: PLM HMM 1 μm Ni₈₁Fe₁₉ / 1 μm Ni₄₅Fe₅₅Sn_(0.3)

[0057] Structure B had no spacer layer between the PLM and HMM layers,as shown in FIG. 1, but was otherwise identical to Structure A.

[0058]FIGS. 3A and 3B show the results of measurement of easy axis loopswhich indicate that Structure B, shown in FIG. 3B has one compositecoercivity; whereas Structure A, shown in FIG. 3A, possesses thecoercivities of both materials.

[0059] It is evident that the 100 Å thick nonmagnetic copper spacerlayer SP effectively separates the magnetization of the Ni₄₅Fe₅₅Sn_(0.3)layer and the magnetization of the Ni₈₁Fe₁₉ layer. The magneticseparation provided by the copper spacer layer SP makes the HMM layercapable of carrying high-intensity flux without adversely disturbing theremanent state of the PLM layer S2B. This feature is used to build ashared pole in accordance with the embodiment shown in FIG. 2 of thisinvention.

[0060] By partially trimming the structure of head 10 or 10′ with anion-beam, the track width of write poles UP/LP and UP/LP′ isself-aligned. Thus unwanted side writing can be minimized further.

PROCESS Structure A Electrodeposition

[0061] 1. To build up a structure, a Permalloy seed-layer is depositedby sputtering. Referring to FIG. 4A, the device 10′ of FIG. 2 is shownin an early stage of manufacture during which a metal seed-layer SL issputtered onto the surface of read gap layer RG and photoresist framePR1 is applied to the surface of seed-layer SL by a photolithographicexposure and development process.

[0062] 2. Referring to FIG. 4B a lithography process is applied to thedevice 10′ of FIG. 4A to form a shared pole pattern.

[0063] The Permalloy PLM layer S2A has been frame-plated onto seed-layerSL to a thickness of about 1 μm (one micrometer) through the shared polemask PR1.

[0064] By using a sophisticated auxiliary electrode-design (J. ECS, 137,110-117, (1990)), one can achieve, a thickness variation within ±0.1 μm.

[0065] 3. Referring to FIG. 4C, the PLM layer S2A has been selectivelyelectroplated through the photoresist pattern. The device 10′ of FIG. 4Bis shown after the step was taken at the end of the plating of layer S2Aof switching to plating a non-magnetic thin copper spacer layer SPplating with a thickness of about 100 Å.

[0066] 4. Referring to FIG. 4D the device 10′ of FIG. 4C is shown afterthe step was taken at the end of plating of copper spacer layer SP ofswitching to forming by plating bath (plate second part of shared pole).

[0067] 5. Referring to FIG. 4E the device 10′ of FIG. 4D is shown afterplanarization with the photoresist frame PR1 remaining in placeplanarizing the HMM layer S2B to form the top shared pole layer S2B′ byCMP (Chemical-Mechanical Polishing/Planarization). Instead of resistremoval, the device 10′ has been chemically-mechanically polished.

[0068] 6. Referring to FIG. 4F the device 10′ of FIG. 4E is shown afteretching away the exposed portions of the field area PLM layer S2A,spacer layer SP, top shared pole layer S2B′ and seed layer SL outside ofthe photoresist frame PR1. Due to improvement of head performance, thisplanarization step is employed for flattening topography resulting fromthe magnetoresistive (MR) sensor and conductors. With the metalplanarization process, it is difficult to have a good uniformity acrossthe wafer. The variation of thickness of layer S2B′ can be as large as±seven tenths of a micrometer (±0.7 μm) which would result in a largethickness variation of upper HMM layer S2B′. The precision of thethickness of upper HMM layer S2B′ is critical for eliminatingsaturation, which can cause a large writing fringe field. The metallayer surface of upper HMM layer S2B′ is flattened and the resist PR1still remains.

[0069] 7. Referring to FIG. 4G the device 10′ of FIG. 4F is shown afterstripping the photoresist frame PR1.

[0070] Above the upper HMM layer S2B′ are formed the write gap layer WGalong with the coil (not shown) and top HMM pole layer PL.

[0071] A new photoresist mask PR2 has been formed on top of write gaplayer WG with an opening centered above magnetoresistive (MR) sensorstripe MRS. A top HMM pole layer PL has been plated into the opening inmask PR2. An excess thickness and width of top pole layer PL is used tocompensate for Ion-Beam Etching (IBE) which is used in step 8 below totrim the HMM layers of device 10′.

[0072] 8. Referring to FIG. 4H the device 10′ of FIG. 4G is shown afterstripping away the photoresist mask PR2. Because, the top HMM pole layerPL was plated after the surface was polished, the variation of HMM layerthickness of layer PL when forming pole P could be controlled only bythe plating process parameters which are employed.

[0073] 9. Referring to FIG. 4I the device 10′ of FIG. 4G is shown afterthe HMM top pole layer PL has been used as a trimming mask and the IBEprocess has been used to trim the shared pole LP′. The width of HMM toppole layer PL has been narrowed by the ion beam etching process. Thetrimming time will be defined by the thickness of the HMM layers S2A andS2B′. The ion beam etching is modified in duration as a function ofdistance from the edge of upper pole UP of width “N” to the edge of thefirst HMM layer S2A of the lower pole LP.

[0074] The IBE process is operated under computer control by the stepsas follows:

[0075] Step 1 To mill the write gap layer WG and the HMM layer S2B′ withan angle from about 45° to about 35°.

[0076] Step 2 To ion mill the redeposited metal from HMM layer S2B′ byusing a high milling angle.

[0077] By partially ion-beam trimming, the inconsistency of the geometryat write gap layer WG can be avoided. The side writing can be furtherdecreased. This design suggests that both material mismatch and trackwidth inconsistency be pushed to the middle layer (between HMM/PLM) ofshared pole.

Structure B

[0078] In the case of the structure B shown in FIG. 1, the processemployed to produce the structure shown was the same except that step 3was omitted.

[0079] While this invention has been described in terms of the abovespecific embodiment(s), those skilled in the art will recognize that theinvention can be practiced with modifications within the spirit andscope of the appended claims, i.e. that changes can be made in form anddetail, without departing from the spirit and scope of the invention.Accordingly all such changes come within the purview of the presentinvention and the invention encompasses the subject matter of the claimswhich follow.

Having thus described the invention, what is claimed as new anddesirable to be secured by Letters Patent is as follows:
 1. A method ofmanufacturing a merged read/write magnetic recording head comprising:forming a low magnetic moment first magnetic shield layer over asubstrate, forming a read gap layer with a magnetoresistive head oversaid first shield layer, forming a shared pole comprising: a) a lowmagnetic moment second magnetic shield layer over said read gap layer,and b) a high magnetic moment lower pole layer over said second magneticshield layer, forming a write gap layer over said lower pole layer ofsaid shared pole, and forming an upper pole comprising a high magneticmoment pole layer over said write gap layer.
 2. A method in accordancewith claim 1 wherein the steps are performed comprising: said upper polehaving a narrow width “N”, said second magnetic shield layer having awidth “W” over said second magnetic shield layer, narrowing said lowerpole layer and said write gap layer to upper magnetic pole width “N”where width “W” is substantially greater than width “N”, and patterningsaid first high magnetic moment pole layer to magnetic pole width “N” inpart and flaring the remainder of said first high magnetic moment polelayer towards said width “W” of said second magnetic shield layer.
 3. Amethod in accordance with claim 1 wherein the steps are performedcomprising: said upper high magnetic moment pole layer having a narrowwidth “N”, said second magnetic shield layer having a width “W” oversaid second magnetic shield layer, using said upper pole as a mask totrim said upper high magnetic moment layer of said shared pole so thatsaid high magnetic moment layer has the same dimension “N” as said toppole and its bottom part is wider with a width “W”.
 4. A method inaccordance with claim 1 wherein the steps are performed comprising:forming a nonmagnetic spacer layer over said low magnetic moment, secondmagnetic shield layer, and below said lower pole layer.
 5. A method inaccordance with claim 1 wherein the steps are performed comprising: saidlow magnetic moment second magnetic shield layer over said read gaplayer is formed of a material selected from the group consisting ofmetals and alloys having soft-magnetic properties including Permalloy,NiFeCr, NiFeMo, NiFeW, NiFePd, NiFeCu, and NiFeCo, and said lower polelayer is formed of a material selected from the group consisting ofNi₄₅Fe₅₅, Ni₄₅Fe₅₅Sn, CoNiFe, CoFeCu, Ni₄₅Fe₅₅Cr, and Ni₄₅Fe₅₅Mo.
 6. Amethod in accordance with claim 1 wherein the steps are performedcomprising: forming a seed layer over said read gap layer prior toplating said low magnetic moment second magnetic shield layer.
 7. Amethod in accordance with claim 1 wherein the steps are performedcomprising: sputtering a PLM nickel-iron seed layer over said read gaplayer prior to plating said low magnetic moment second magnetic shieldlayer.
 8. A method in accordance with claim 1 wherein the steps areperformed comprising: said upper high magnetic moment pole layer havinga narrow width “N”, said second magnetic shield layer having a width “W”over said second magnetic shield layer, employing ion beam etching tonarrow said lower pole layer and said write gap layer to upper magneticpole width “N” where width “W” is substantially greater than width “N”,and employing ion beam etching to pattern said first high magneticmoment pole layer to magnetic pole width “N” in part and flaring theremainder of said first high magnetic moment pole layer towards saidwidth “W” of said second magnetic shield layer.
 9. A method inaccordance with claim 1 wherein the steps are performed comprising:sputtering a PLM nickel-iron seed layer over said read gap layer priorto plating said low magnetic moment second magnetic shield layer, saidupper high magnetic moment pole layer having a narrow width “N”, saidsecond magnetic shield layer having a width “W” over said secondmagnetic shield layer, employing ion beam etching to narrow said lowerpole and said write gap layer to upper magnetic pole width “N” wherewidth “W” is substantially greater than width “N”, and employing ionbeam etching to pattern said first high magnetic moment pole layer tomagnetic pole width “N” in part and flaring the remainder of said firsthigh magnetic moment pole layer towards said width “W” of said secondmagnetic shield layer.
 10. A method in accordance with claim 1 whereinthe steps are performed comprising: sputtering a PLM nickel-iron seedlayer over said read gap layer prior to plating said low magnetic momentsecond magnetic shield layer, said upper high magnetic moment pole layerhaving a narrow width “N”, said second magnetic shield layer having awidth “W” over said second magnetic shield layer, employing ion beametching to narrow said lower pole layer and said write gap layer toupper magnetic pole width “N” where width “W” is substantially greaterthan width “N”, employing ion beam etching to pattern said first highmagnetic moment pole layer to magnetic pole width “N” in part andflaring the remainder of said first high magnetic moment pole layertowards said width “W” of said second magnetic shield layer, said lowmagnetic moment second magnetic shield layer over said read gap layer isformed of a material selected from the group consisting of metals andalloys having soft-magnetic properties including Permalloy, NiFeCr,NiFeMo, NiFeW, NiFePd, NiFeCu, and NiFeCo, and said lower pole layer isformed of a material selected from the group consisting of Ni₄₅Fe₅₅,Ni₄₅Fe₅₅Sn, CoNiFe, CoFeCu, Ni₄₅Fe₅₅Cr, and Ni₄₅Fe₅₅Mo.
 11. A method ofmanufacturing a magnetic recording head comprising: forming a lowmagnetic moment first magnetic shield layer over a substrate, forming aread gap layer with a magnetoresistive head over said first shieldlayer, forming a seed layer over said read gap layer, forming a framemask with width “W” over said seed layer, forming a low magnetic momentsecond magnetic shield layer over said read gap layer over said seedlayer, forming a non-magnetic spacer layer over said second magneticshield layer, forming a first high magnetic moment pole layer over saidsecond magnetic shield layer, forming a write gap layer over said firsthigh magnetic moment pole layer, forming a second high magnetic momentpole layer over said write gap layer, and outside of said frame maskperforming the step of removing the portions said second magnetic shieldlayer, said first high magnetic moment pole layer, said write gap layer,said second high magnetic moment pole, and said seed layer.
 12. A methodin accordance with claim 11 wherein the steps are performed comprising:said upper high magnetic moment pole layer having a narrow width “N”,said second magnetic shield layer having a width “W” over said secondmagnetic shield layer, narrowing said lower pole layer and said writegap layer to upper magnetic pole width “N” where width “W” issubstantially greater than width “N”, and patterning said first highmagnetic moment pole layer to magnetic pole width “N” in part andflaring the remainder of said first high magnetic moment pole layertowards said width “W” of said second magnetic shield layer.
 13. Amethod in accordance with claim 11 wherein the steps are performedcomprising: said upper high magnetic moment pole layer having a narrowwidth “N”, said second magnetic shield layer having a width “W” oversaid second magnetic shield layer, using said upper pole as a mask totrim said upper high magnetic moment layer of said shared pole so thatsaid high magnetic moment layer has the same dimension “N” as said toppole and its bottom part is wider with a width “W”.
 14. A method inaccordance with claim 11 wherein the steps are performed comprising:forming a nonmagnetic spacer layer over said low magnetic moment, secondmagnetic shield layer, and below said lower pole layer.
 15. A method inaccordance with claim 11 wherein the steps are performed comprising:said low magnetic moment second magnetic shield layer over said read gaplayer is formed of a material selected from the group consisting ofmetals and alloys having soft-magnetic properties including Permalloy,NiFeCr, NiFeMo, NiFeW, NiFePd, NiFeCu, and NiFeCo, and said lower polelayer is formed of a material selected from the group consisting ofNi₄₅Fe₅₅, Ni₄₅Fe₅₅Sn, CoNiFe, CoFeCu, Ni₄₅Fe₅₅Cr, and Ni₄₅Fe₅₅Mo.
 16. Amethod in accordance with claim 11 wherein the steps are performedcomprising: forming a seed layer over said read gap layer prior toplating said low magnetic moment second magnetic shield layer.
 17. Amethod in accordance with claim 11 wherein the steps are performedcomprising: sputtering a PLM nickel-iron seed layer over said read gaplayer prior to plating said low magnetic moment second magnetic shieldlayer.
 18. A method in accordance with claim 11 wherein the steps areperformed comprising: said upper high magnetic moment pole layer havinga narrow width “N”, said second magnetic shield layer having a width “W”over said second magnetic shield layer, employing ion beam etching tonarrow said lower pole layer and said write gap layer to upper magneticpole width “N” where width “W” is substantially greater than width “N”,and employing ion beam etching to pattern said first high magneticmoment pole layer to magnetic pole width “N” in part and flaring theremainder of said first high magnetic moment pole layer towards saidwidth “W” of said second magnetic shield layer.
 19. A method inaccordance with claim 11 wherein the steps are performed comprising:sputtering a PLM nickel-iron seed layer over said read gap layer priorto plating said low magnetic moment second magnetic shield layer, saidupper high magnetic moment pole layer having a narrow width “N”, saidsecond magnetic shield layer having a width “W” over said secondmagnetic shield layer, employing ion beam etching to narrow said lowerpole layer and said write gap layer to upper magnetic pole width “N”where width “W” is substantially greater than width “N”, and employingion beam etching to pattern said first high magnetic moment pole layerto magnetic pole width “N” in part and flaring the remainder of saidfirst high magnetic moment pole layer towards said width “W” of saidsecond magnetic shield layer.
 20. A method in accordance with claim 11wherein the steps are performed comprising: sputtering a PLM nickel-ironseed layer over said read gap layer prior to plating said low magneticmoment second magnetic shield layer, said upper high magnetic momentpole layer having a narrow width “N”, said second magnetic shield layerhaving a width “W” over said second magnetic shield layer, employing ionbeam etching to narrow said lower pole layer and said write gap layer toupper magnetic pole width “N” where width “W” is substantially greaterthan width “N”, employing ion beam etching to pattern said first highmagnetic moment pole layer to magnetic pole width “N” in part andflaring the remainder of said first high magnetic moment pole layertowards said width “W” of said second magnetic shield layer, said lowmagnetic moment second magnetic shield layer over said read gap layer isformed of a material selected from the group consisting of metals andalloys having soft-magnetic properties including Permalloy, NiFeCr,NiFeMo, NiFeW, NiFePd, NiFeCu, and NiFeCo, and said lower pole layer isformed of a material selected from the group consisting of Ni₄₅Fe₅₅,Ni₄₅Fe₅₅Sn, CoNiFe, CoFeCu, Ni₄₅Fe₅₅Cr, and Ni₄₅Fe₅₅Mo.
 21. A magneticrecording head comprising: a merged magnetoresistive read head/inductivewrite head, said read head having a composite shared pole consisting ofa PLM layer laminated with an HMM lower pole layer and an HMM upper poleand said write head having a top pole made of HMM material.
 22. A headin accordance with claim 21 wherein: said shared pole is a layeredstructure of said PLM layer, a non-magnetic spacer layer and said HMMlower pole layer.
 23. A head in accordance with claim 21 wherein: saidPLM layer is composed of a material selected from electroplated metalsand alloys having soft-magnetic properties.
 24. A head in accordancewith claim 21 wherein: said PLM layer is composed of a material selectedfrom the group consisting of Permalloy, NiFeCr, NiFeMo, NiFeW, NiFePd,NiFeCu, NiFeCo, and said HMM lower pole is composed of a materialselected from the group consisting of Ni₄₅Fe₅₅, Ni₄₅Fe₅₅Sn, CoNiFe,CoFeCu, Ni₄₅Fe₅₅Cr, and Ni₄₅Fe₅₅Mo.
 25. A magnetic recording headcomprising: a merged magnetoresistive read head/inductive write head, acomposite shared shield/pole consisting of a PLM layer above said readhead laminated with a spacer layer and an HMM lower pole layer and anHMM upper pole, and a top pole made of HMM material.
 26. A head inaccordance with claim 25 wherein said spacer layer comprisesnon-magnetic material selected from the metals and metal alloys.
 27. Amagnetic recording head comprising: a magnetoresistive merged headhaving a top pole made of HMM material, a composite shared poleconsisting of a PLM layer laminated with a spacer layer and an HMM lowerpole layer and an HMM upper pole, and said spacer layer comprisesnon-magnetic material selected from the metals and metal alloys.
 28. Amerged read/write magnetic recording head comprising: a low magneticmoment first magnetic shield layer over a substrate, and a read gaplayer with a magnetoresistive head over said first shield layer, ashared pole comprising: a) a low magnetic moment second magnetic shieldlayer over said read gap layer, and b) a high magnetic moment lower polelayer over said second magnetic shield layer, a write gap layer oversaid first high magnetic moment pole layer of said shared pole, and anupper pole comprising a high magnetic moment pole layer over said writegap layer.
 29. A head in accordance with claim 28 wherein: said sharedpole is a layered structure of said PLM layer, a non-magnetic spacerlayer and said HMM lower pole layer.
 30. A head in accordance with claim28 wherein said PLM layer is composed of a material selected fromelectroplated metals and alloys having soft-magnetic properties.
 31. Ahead in accordance with claim 28 wherein said PLM layer is composed of amaterial selected from the group consisting of Permalloy, NiFeCr,NiFeMo, NiFeW, NiFePd, NiFeCu, NiFeCo, and said HMM lower pole iscomposed of a material selected from the group consisting of Ni₄₅Fe₅₅,Ni₄₅Fe₅₅Sn, CoNiFe, CoFeCu, Ni₄₅Fe₅₅Cr, and Ni₄₅Fe₅₅Mo.
 32. A magneticrecording head comprising: a merged magnetoresistive read head/inductivewrite head, a composite shared shield/pole consisting of a PLM layerabove said read head laminated with a spacer layer and an HMM lower polelayer and an HMM upper pole, and a top pole made of HMM material.
 33. Ahead in accordance with claim 32 wherein said spacer layer comprisesnon-magnetic material selected from the metals and metal alloys.
 34. Ahead in accordance with claim 32 wherein said spacer layer comprises athin copper (Cu) spacer layer.
 35. A magnetic recording head comprising:a magnetoresistive merged head having a top pole made of HMM material, acomposite shared pole consisting of a PLM layer laminated with a spacerlayer and an HMM lower pole layer and an HMM upper pole, and said spacerlayer comprises non-magnetic material selected from the metals and metalalloys.
 36. A magnetic recording head comprising: a low magnetic momentfirst magnetic shield layer over a substrate, a read gap layer with amagnetoresistive head over said first shield layer, a seed layer oversaid read gap layer, a frame mask with width “W” over said seed layer, aplated low magnetic moment second magnetic shield layer over said readgap layer over said seed layer, a plated non-magnetic spacer layer oversaid second magnetic shield layer, a plated first high magnetic momentpole layer over said second magnetic shield layer, a write gap layerover said first high magnetic moment pole layer, a second high magneticmoment pole layer over said write gap layer, and outside of said framemask performing the step of removing the portions said second magneticshield layer, said first high magnetic moment pole layer, said write gaplayer, said second high magnetic moment pole, and said seed layer.
 37. Ahead in accordance with claim 36 comprising: said upper high magneticmoment pole layer having a narrow width “N”, said second magnetic shieldlayer having a width “W” over said second magnetic shield layer, saidlower pole layer and said write gap layer narrowing to upper magneticpole width “N” where width “W” is substantially greater than width “N”,and said first high magnetic moment pole layer patterned to magneticpole width “N” in part and the remainder of said first high magneticmoment pole layer flared towards said width “W” of said second magneticshield layer.
 38. A head in accordance with claim 36 comprising: saidupper high magnetic moment pole layer having a narrow width “N”, saidsecond magnetic shield layer having a width “W” over said secondmagnetic shield layer, using said upper pole as a mask to trim saidupper high magnetic moment layer of said shared pole so that said highmagnetic moment layer has the same dimension “N” as said top pole andits bottom part is wider with a width “W”.
 39. A head in accordance withclaim 36 comprising: a nonmagnetic spacer layer formed over said lowmagnetic moment, second magnetic shield layer, and below said lower polelayer.
 40. A head in accordance with claim 36 comprising: said lowmagnetic moment second magnetic shield layer over said read gap layer isformed of a material selected from the group consisting of metals andalloys having soft-magnetic properties including Permalloy, NiFeCr,NiFeMo, NiFeW, NiFePd, NiFeCu, and NiFeCo, and said lower pole layer isformed of a material selected from the group consisting of Ni₄₅Fe₅₅,Ni₄₅Fe₅₅Sn, CoNiFe, CoFeCu, Ni₄₅Fe₅₅Cr, and Ni₄₅Fe₅₅Mo.
 41. A head inaccordance with claim 36 comprising: a seed layer formed over said readgap layer below said plated low magnetic moment second magnetic shieldlayer.
 42. A head in accordance with claim 36 comprising: a sputteredPLM nickel-iron seed layer over said read gap layer below said platedsaid low magnetic moment second magnetic shield layer.
 43. A head inaccordance with claim 36 comprising: said upper high magnetic momentpole layer having a narrow width “N”, said second magnetic shield layerhaving a width “W” over said second magnetic shield layer, said lowerpole layer and said write gap layer narrowed to upper magnetic polewidth “N” where width “W” is substantially greater than width “N”, andsaid first high magnetic moment pole layer patterned to magnetic polewidth “N” in part and the remainder of said first high magnetic momentpole layer flaring towards said width “W” of said second magnetic shieldlayer.
 44. A head in accordance with claim 36 comprising: a sputteredPLM nickel-iron seed layer over said read gap layer prior to platingsaid low magnetic moment second magnetic shield layer, said upper highmagnetic moment pole layer having a narrow width “N”, said secondmagnetic shield layer having a width “W” over said second magneticshield layer, said lower pole layer and said write gap layer narrowed toupper magnetic pole width “N” where width “W” is substantially greaterthan width “N”, and said first high magnetic moment pole layer patternedto magnetic pole width “N” in part and flaring the remainder of saidfirst high magnetic moment pole layer towards said width “W” of saidsecond magnetic shield layer.
 45. A head in accordance with claim 36comprising: said seed layer comprising a sputtered PLM nickel-iron layerover said read gap layer below said plated low magnetic moment secondmagnetic shield layer, said upper high magnetic moment pole layer havinga narrow width “N”, said second magnetic shield layer having a width “W”over said second magnetic shield layer, said lower pole layer and saidwrite gap layer having been narrowed by ion beam etching to uppermagnetic pole width “N” where width “W” is substantially greater thanwidth “N”, said first high magnetic moment pole layer having been ionbeam etching to magnetic pole width “N” in part and the remainder ofsaid first high magnetic moment pole layer flaring towards said width“W” of said second magnetic shield layer, said low magnetic momentsecond magnetic shield layer over said read gap layer is formed of amaterial selected from the group consisting of metals and alloys havingsoft-magnetic properties including Permalloy, NiFeCr, NiFeMo, NiFeW,NiFePd, NiFeCu, and NiFeCo, and said lower pole layer is formed of amaterial selected from the group consisting of Ni₄₅Fe₅₅, Ni₄₅Fe₅₅Sn,CoNiFe, CoFeCu, Ni₄₅Fe₅₅Cr, and Ni₄₅Fe₅₅Mo.